/* styles.css */

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

body {
  background-color: #E0FFFF;  /* ???????????? */
  margin: 0;
  padding: 20px;
}

.main-container {
  background-color: rgba(255,255,255,0.85);
  padding: 30px;
  border-radius: 15px;
  max-width: 900px;
  margin: 0 auto;
  box-shadow: 0 0 15px rgba(0,0,0,0.1);
}